This chapter reviews vertebrate α-synuclein transgenic mouse models which have led to substantial advances in understanding the role of α-synuclein in pathogenic processes that are relevant to Parkinson's disease (PD). Mutations in the gene coding for leucine rich repeat kinase-2 (LRRK2) also lead to autosomal-dominant PD. LRRK2 is a large protein containing multiple functional domains including a GTPase and kinase domain. Of the various α-synuclein transgenic mice that have been generated over the years, the models using the murine Thy-1 promoter and the murine prion promoter recapitulate most if not all the pathogenic features of PD, except for degeneration of dopamine neurons. Transgenic mice overexpressing α-synuclein under either promoter develop α-synucleinopathy in neurons and overlapping brain regions with predominate pathology in spinal motor neurons, deep cerebellar nuclei, pontine reticular nuclei and the red nucleus. The neuronal populations are particularly vulnerable to α-synuclein-induced neurodegeneration in mice. It is suggested that the α-synuclein transgenic models can be used to explore the molecular basis of cell death induced by α-synuclein.